151 ideas
| 7504 | Modern science comes from Descartes' view that knowledge doesn't need moral purity [Descartes, by Foucault] |
| Full Idea: Before Descartes, one could not be impure, immoral, and know the truth. After Descartes, direct evidence is enough, and we have a nonascetic subject of knowledge; this change makes possible the institutionalisation of modern science. | |
| From: report of René Descartes (Meditations [1641]) by Michel Foucault - On the Genealogy of Ethics | |
| A reaction: I would have thought Gassendi and the British Empiricists would be a more plausible source for this shift of attitude. Plato would relegate modern science to a lower level of knowledge. |
| 12274 | Begin examination with basics, and subdivide till you can go no further [Aristotle] |
| Full Idea: The examination must be carried on and begin from the primary classes and then go on step by step until further division is impossible. | |
| From: Aristotle (Topics [c.331 BCE], 109b17) | |
| A reaction: This is a good slogan for the analytic approach to thought. I take Aristotle (or possibly Socrates) to be the father of analysis, not Frege (though see Idea 9840). (He may be thinking of the tableau method of proof). |
| 1569 | Descartes impoverished the classical idea of logos, and it no longer covered human experience [Roochnik on Descartes] |
| Full Idea: Descartes attacked and fundamentally altered classical logos. The result is an impoverished conception of reason, one that is unable to do justice to the significance and value of human experience. | |
| From: comment on René Descartes (Meditations [1641]) by David Roochnik - The Tragedy of Reason Prol. Xii |
| 2248 | Reason says don't assent to uncertain principles, just as much as totally false ones [Descartes] |
| Full Idea: Reason now persuades me that I should withhold my assent no less carefully from opinions that are not completely certain and indubitable than I would from those that are patently false. | |
| From: René Descartes (Meditations [1641], §1.18) |
| 2857 | Since Plato all philosophers have followed the herd, except Descartes, stuck in superficial reason [Nietzsche on Descartes] |
| Full Idea: Since Plato all philosophers have followed moral 'instinct', or 'faith', or (as I call it) 'the herd'. One might exclude Descartes, the father of rationalism, who recognised only reason - but reason is only an instrument, and Descartes was superficial. | |
| From: comment on René Descartes (Meditations [1641]) by Friedrich Nietzsche - Beyond Good and Evil §191 |
| 12260 | Dialectic starts from generally accepted opinions [Aristotle] |
| Full Idea: Reasoning is dialectical which reasons from generally accepted opinions. | |
| From: Aristotle (Topics [c.331 BCE], 100a30) | |
| A reaction: This is right at the heart of Aristotle's philosophical method, and Greek thinking generally. There are nice modern debates about 'folk' understanding, derived from science (e.g. quantum theory) which suggest that starting from normal views is a bad idea. |
| 12291 | There can't be one definition of two things, or two definitions of the same thing [Aristotle] |
| Full Idea: There cannot possibly be one definition of two things, or two definitions of the same thing. | |
| From: Aristotle (Topics [c.331 BCE], 154a11) | |
| A reaction: The second half of this is much bolder and more controversial, and plenty of modern thinkers would flatly reject it. Are definitions contextual, that is, designed for some specific human purpose. Must definitions be of causes? |
| 12292 | Definitions are easily destroyed, since they can contain very many assertions [Aristotle] |
| Full Idea: A definition is the easiest of all things to destroy; for, since it contains many assertions, the opportunities which it offers are very numerous, and the more abundant the material, the more quickly the reasoning can set to work. | |
| From: Aristotle (Topics [c.331 BCE], 155a03) | |
| A reaction: I quote this to show that Aristotle expected many definitions to be very long affairs (maybe even of book length?) |
| 12261 | Differentia are generic, and belong with genus [Aristotle] |
| Full Idea: The differentia, being generic in character, should be ranged with the genus. | |
| From: Aristotle (Topics [c.331 BCE], 101b18) | |
| A reaction: This does not mean that naming the differentia amounts to mere classification. I presume we can only state individual differences by using a language which is crammed full of universals. |
| 12263 | 'Genus' is part of the essence shared among several things [Aristotle] |
| Full Idea: A 'genus' is that which is predicated in the category of essence of several things which differ in kind. | |
| From: Aristotle (Topics [c.331 BCE], 102a32) | |
| A reaction: Hence a genus is likely to be expressed by a universal, a one-over-many. A particular will be a highly individual collection of various genera, but what ensures the uniqueness of each thing, if they are indiscernible? |
| 12272 | We describe the essence of a particular thing by means of its differentiae [Aristotle] |
| Full Idea: We usually isolate the appropriate description of the essence of a particular thing by means of the differentiae which are peculiar to it. | |
| From: Aristotle (Topics [c.331 BCE], 108b05) | |
| A reaction: I take this to be important for showing the definition is more than mere categorisation. A good definition homes in the particular, by gradually narrowing down the differentiae. |
| 12279 | The differentia indicate the qualities, but not the essence [Aristotle] |
| Full Idea: No differentia indicates the essence [ti estin], but rather some quality, such as 'pedestrian' or 'biped'. | |
| From: Aristotle (Topics [c.331 BCE], 122b17) | |
| A reaction: We must disentangle this, since essence is what is definable, and definition seems to give us the essence, and yet it appears that definition only requires genus and differentia. Differentiae seem to be both generic and fine-grained. See Idea 12280! |
| 12283 | In definitions the first term to be assigned ought to be the genus [Aristotle] |
| Full Idea: In definitions the first term to be assigned ought to be the genus. | |
| From: Aristotle (Topics [c.331 BCE], 132a12) | |
| A reaction: We mustn't be deluded into thinking that nothing else is required. I take the increasing refinement of differentiae to be where the real action is. The genus gives you 70% of the explanation. |
| 12289 | The genera and the differentiae are part of the essence [Aristotle] |
| Full Idea: The genera and the differentiae are predicated in the category of essence. | |
| From: Aristotle (Topics [c.331 BCE], 153a19) | |
| A reaction: The definition is words, and the essence is real, so our best definition might not fully attain to the essence. Aristotle has us reaching out to the world through our definitions. |
| 12285 | The definition is peculiar to one thing, not common to many [Aristotle] |
| Full Idea: The definition ought to be peculiar to one thing, not common to many. | |
| From: Aristotle (Topics [c.331 BCE], 149b24) | |
| A reaction: I take this to be very important, against those who think that definition is no more than mere categorisation. To explain, you must get down to the level of the individual. We must explain that uniquely docile tiger. |
| 2290 | Once it is clear that there is a God who is no deceiver, I conclude that clear and distinct perceptions must be true [Descartes] |
| Full Idea: Once I perceived that there is a God,…and that he is no deceiver, I then concluded that everything that I clearly and distinctly perceived is necessarily true. | |
| From: René Descartes (Meditations [1641], §5.70) | |
| A reaction: spotted by Arnauld |
| 3641 | It is circular to make truth depend on believing God's existence is true [Arnauld on Descartes] |
| Full Idea: How does the author avoid reasoning in a circle when he says that we are sure that what we clearly and distinctly perceive is true only because God exists? But we can be sure that God exists only because we clearly and distinctly perceive this. | |
| From: comment on René Descartes (Meditations [1641], §5.71) by Antoine Arnauld - Objections to 'Meditations' (Fourth) 214 |
| 4524 | Descartes is right that in the Christian view only God can guarantee the reliability of senses [Nietzsche on Descartes] |
| Full Idea: Even Descartes had a notion that in a Christian mode of thought (where God is a good creator), only God's veracity guarantees to us the judgements of our senses. | |
| From: comment on René Descartes (Meditations [1641], §5.71) by Friedrich Nietzsche - The Will to Power (notebooks) §436 | |
| A reaction: An unusual defence of the notorious Cartesian Circle. Of course, Descartes claims that God guarantees reason (as 'clear and distinct conception'), not senses, and only reason led Descartes to God. |
| 2266 | My general rule is that everything that I perceive clearly and distinctly is true [Descartes] |
| Full Idea: I now seem able to posit as a general rule that everything I very clearly and distinctly perceive is true. | |
| From: René Descartes (Meditations [1641], §3.35) |
| 4301 | Someone may think a thing is 'clear and distinct', but be wrong [Leibniz on Descartes] |
| Full Idea: Leibniz objected to Descartes' theory of truth, saying that people may think something is clear and distinct, and yet be wrong. | |
| From: comment on René Descartes (Meditations [1641], §3.36) by Gottfried Leibniz - works | |
| A reaction: Quite so. Descartes has misunderstood what sort of concept 'truth' is meant to be. It's the usual confusion of epistemology and metaphysics. Truth is not a feature of the human mind. |
| 10054 | Arithmetic and geometry achieve some certainty without worrying about existence [Descartes] |
| Full Idea: Arithmetic, geometry and sciences of that kind only treat of things without taking any great trouble to ascertain whether they are actually existent or not, and contain some measure of certainty. | |
| From: René Descartes (Meditations [1641], §1), quoted by Alan Musgrave - Logicism Revisited §4 | |
| A reaction: This is Musgrave's earliest quotation which seems to take the if-thenist view. |
| 11261 | Puzzles arise when reasoning seems equal on both sides [Aristotle] |
| Full Idea: The equality of opposite reasonings is the cause of aporia; for it is when we reason on both [sides of a question] and it appears to us that everything can come about either way, that we are in a state of aporia about which of the two ways to take up. | |
| From: Aristotle (Topics [c.331 BCE], 145b17), quoted by Vassilis Politis - Aristotle and the Metaphysics 3.1 | |
| A reaction: Other philosophers give up on the subject in this situation, but I love Aristotle because he takes this to be the place where philosophy begins. |
| 2252 | Surely maths is true even if I am dreaming? [Descartes] |
| Full Idea: Surely whether I am asleep or awake, two plus three makes five, and a square does not have more than four sides. | |
| From: René Descartes (Meditations [1641], §1.20) |
| 2430 | I can learn the concepts of duration and number just from observing my own thoughts [Descartes] |
| Full Idea: When I think that I exist now, and recollect that I existed in the past, and when I conceive various thoughts, the number of which I know, then I acquire the ideas of duration and number which I can thereafter transfer to all the other objects I wish. | |
| From: René Descartes (Meditations [1641], §3.44) |
| 12273 | Unit is the starting point of number [Aristotle] |
| Full Idea: They say that the unit [monada] is the starting point of number (and the point the starting-point of a line). | |
| From: Aristotle (Topics [c.331 BCE], 108b30) | |
| A reaction: Yes, despite Frege's objections in the early part of the 'Grundlagen' (1884). I take arithmetic to be rooted in counting, despite all abstract definitions of number by Frege and Dedekind. Identity gives the unit, which is countable. See also Topics 141b9 |
| 12267 | There are ten categories: essence, quantity, quality, relation, place, time, position, state, activity, passivity [Aristotle] |
| Full Idea: The four main types of predicates fall into ten categories: essence, quantity, quality, relation, place, time, position, state, activity, passivity. | |
| From: Aristotle (Topics [c.331 BCE], 103b20) | |
| A reaction: These are the standard ten categories of Aristotle. He is notable for the divisions not being sharp, and ten being a rough total. He is well aware of the limits of precision in such matters. |
| 12282 | An individual property has to exist (in past, present or future) [Aristotle] |
| Full Idea: If it does not at present exist, or, if it has not existed in the past, or if it is not going to exist in the future, it will not be a property [idion] at all. | |
| From: Aristotle (Topics [c.331 BCE], 129a27) | |
| A reaction: This seems to cramp our style in counterfactual discussion. Can't we even mention an individual property if we believe that it will never exist. Utopian political discussion will have to cease! |
| 12264 | An 'accident' is something which may possibly either belong or not belong to a thing [Aristotle] |
| Full Idea: An 'accident' [sumbebekos] is something which may possibly either belong or not belong to any one and the self-same thing, such as 'sitting posture' or 'whiteness'. This is the best definition, because it tells us the essential meaning of the term itself. | |
| From: Aristotle (Topics [c.331 BCE], 102b07) | |
| A reaction: Thus a car could be red, or not red. Accidents are contingent. It does not follow that necessary properties are essential (see Idea 12262). There are accidents [sumbebekos], propria [idion] and essences [to ti en einai]. |
| 12280 | Genus gives the essence better than the differentiae do [Aristotle] |
| Full Idea: In assigning the essence [ti estin], it is more appropriate to state the genus than the differentiae; for he who describes 'man' as an 'animal' indicates his essence better than he who describes him as 'pedestrian'. | |
| From: Aristotle (Topics [c.331 BCE], 128a24) | |
| A reaction: See Idea 12279. This idea is only part of the story. My reading of this is simply that assigning a genus gives more information. We learn more about him when we say he is a man than when we say he is Socrates. |
| 2297 | If I can separate two things in my understanding, then God can separate them in reality [Descartes] |
| Full Idea: My ability clearly and distinctly to understand one thing without another suffices to make me certain that the one thing is different from the other, since they can be separated from each other (at least by God). | |
| From: René Descartes (Meditations [1641], §6.78) |
| 3628 | Substance cannot be conceived or explained to others [Gassendi on Descartes] |
| Full Idea: The alleged naked, or rather hidden, substance of wax is something that we can neither ourselves conceive nor explain to others. | |
| From: comment on René Descartes (Meditations [1641], §2.31) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 273 |
| 16631 | If we remove surface qualities from wax, we have an extended, flexible, changeable thing [Descartes] |
| Full Idea: After taking away what does not belong to the wax, let us see what is left: surely, it is nothing other than a thing that is extended, flexible and changeable. | |
| From: René Descartes (Meditations [1641], (VII:30-1)), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.2 | |
| A reaction: Aristotle worried about nothing being left when you 'stripped' an object, so this could be seen as a positive contribution to scholastic philosophy. Why is the substrate 'flexible'? He talks elsewhere of taking the clothes off the wax and seeing it naked. |
| 13269 | In the case of a house the parts can exist without the whole, so parts are not the whole [Aristotle] |
| Full Idea: In the case of a house, where the process of compounding the parts is obvious, though the parts exist, there is no reason why the whole should not be non-existent, and so the parts are not the same as the whole. | |
| From: Aristotle (Topics [c.331 BCE], 150a19) | |
| A reaction: Compare buying a piece of furniture, and being surprised to discover, when it is delivered, that it is self-assembly. This idea is a simple refutation of the claims of classical mereology, that wholes are just some parts. Aristotle uses modal claims. |
| 12284 | Everything that is has one single essence [Aristotle] |
| Full Idea: Everything that is has one single essence [en esti to einai]. | |
| From: Aristotle (Topics [c.331 BCE], 141a36) | |
| A reaction: Does this include vague objects, and abstract 'objects'? Sceptics might ask what grounds this claim. Does Dr Jeckyll have two essences? |
| 17865 | Descartes gives an essence by an encapsulating formula [Descartes, by Almog] |
| Full Idea: For Descartes in providing an essence for an item [such as God, wax, or a mathematical kind] we provide an encapsulating formula defining the phenomenon. | |
| From: report of René Descartes (Meditations [1641]) by Joseph Almog - Nature Without Essence I | |
| A reaction: I argue that this is not what Aristotle intended be an essentialist definition, which can be quite long, like a scientific monograph. Descartes firmly rejected Aristotle's 'substantial form' as essence. |
| 12262 | An 'idion' belongs uniquely to a thing, but is not part of its essence [Aristotle] |
| Full Idea: A property [idion] is something which does not show the essence of a thing but belongs to it alone. ...No one calls anything a property which can possibly belong to something else. | |
| From: Aristotle (Topics [c.331 BCE], 102a18) | |
| A reaction: [See Charlotte Witt 106 on this] 'Property' is clearly a bad translation for such an individual item. Witt uses 'proprium', which is a necessary but nonessential property of something. Necessity is NOT the hallmark of essence. See Idea 12266. |
| 12290 | Destruction is dissolution of essence [Aristotle] |
| Full Idea: Destruction is a dissolution of essence. | |
| From: Aristotle (Topics [c.331 BCE], 153b30) | |
| A reaction: [plucked from context!] I can't think of a better way to define destruction, in order to distinguish it from damage. A vase is destroyed when its essential function cannot be recovered. |
| 12286 | If two things are the same, they must have the same source and origin [Aristotle] |
| Full Idea: When things are absolutely the same, their coming-into-being and destruction are also the same and so are the agents of their production and destruction. | |
| From: Aristotle (Topics [c.331 BCE], 152a02) | |
| A reaction: Thus Queen Elizabeth II has to be the result of that particular birth, and from those particular parents, as Kripke says? The inverse may not be true. Do twins have a single origin? Things that fission and then re-fuse differently? etc |
| 12266 | 'Same' is mainly for names or definitions, but also for propria, and for accidents [Aristotle] |
| Full Idea: 'The same' is employed in several senses: its principal sense is for same name or same definition; a second sense occurs when sameness is applied to a property [idiu]; a third sense is applied to an accident. | |
| From: Aristotle (Topics [c.331 BCE], 103a24-33) | |
| A reaction: [compressed] 'Property' is better translated as 'proprium' - a property unique to a particular thing, but not essential - see Idea 12262. Things are made up of essence, propria and accidents, and three ways of being 'the same' are the result. |
| 12287 | Two identical things have the same accidents, they are the same; if the accidents differ, they're different [Aristotle] |
| Full Idea: If two things are the same then any accident of one must also be an accident of the other, and, if one of them is an accident of something else, so must the other be also. For, if there is any discrepancy on these points, obviously they are not the same. | |
| From: Aristotle (Topics [c.331 BCE], 152a36) | |
| A reaction: So what is always called 'Leibniz's Law' should actually be 'Aristotle's Law'! I can't see anything missing from the Aristotle version, but then, since most people think it is pretty obvious, you would expect the great stater of the obvious to get it. |
| 12288 | Numerical sameness and generic sameness are not the same [Aristotle] |
| Full Idea: Things which are the same specifically or generically are not necessarily the same or cannot possibly be the same numerically. | |
| From: Aristotle (Topics [c.331 BCE], 152b32) | |
| A reaction: See also Idea 12266. This looks to me to be a pretty precise anticipation of Peirce's type/token distinction, but without the terminology. It is reassuring that Aristotle spotted it, as that makes it more likely to be a genuine distinction. |
| 12259 | Reasoning is when some results follow necessarily from certain claims [Aristotle] |
| Full Idea: Reasoning [sullogismos] is a discussion in which, certain things having been laid down, something other than these things necessarily results through them. | |
| From: Aristotle (Topics [c.331 BCE], 100a25) | |
| A reaction: This is cited as the standard statement of the nature of logical necessity. One might challenge either the very word 'necessary', or the exact sense of the word employed here. Is it, in fact, metaphysical, or merely analytic? |
| 2301 | We know by thought that what is done cannot be undone [Descartes] |
| Full Idea: Some ideas belong exclusively to the mind, such as perceiving that what has been done cannot be undone, and everything else that is known by the light of nature. | |
| From: René Descartes (Meditations [1641], §6.82) |
| 3642 | Pythagoras' Theorem doesn't cease to be part of the essence of triangles just because we doubt it [Arnauld on Descartes] |
| Full Idea: You can't reason 'I know the triangle is right-angled, but I doubt Pythagoras' Theorem, therefore it does not belong to the essence of right-angled triangles that the square on the hypotenuse is equal to the sum of the squares on the other two sides'. | |
| From: comment on René Descartes (Meditations [1641], §6.78) by Antoine Arnauld - Objections to 'Meditations' (Fourth) 202 |
| 20190 | Belief is not an intellectual state or act, because propositions are affirmed or denied by the will [Descartes, by Zagzebski] |
| Full Idea: Descartes claimed that belief is not purely an intellectual state or act, since it is not the intellect that affirms or denies a proposition proposed for its consideration, but the will. | |
| From: report of René Descartes (Meditations [1641], IV) by Linda Trinkaus Zagzebski - Virtues of the Mind 4.2 | |
| A reaction: This is the canonical idea of 'doxastic voluntarism' - that we choose what to believe or not believe. In modern times this view has become deeply unfashionable. I don't we should wholly reject the possibility of choosing to believe something. |
| 1582 | Labelling slightly doubtful things as false is irrational [Roochnik on Descartes] |
| Full Idea: To declare that which is the least bit dubious as absolutely false is to declare war on logos. | |
| From: comment on René Descartes (Meditations [1641], §1.17) by David Roochnik - The Tragedy of Reason p.72 |
| 2256 | Maybe there is only one certain fact, which is that nothing is certain [Descartes] |
| Full Idea: If I suppose that everything I see is false. Nothing I remember actually existed. I have no senses, and body, shape, extension, movement and place are all chimeras. What then is true? Perhaps just the single fact that nothing is certain. | |
| From: René Descartes (Meditations [1641], §2.24) |
| 1585 | Descartes tried to model reason on maths instead of 'logos' [Roochnik on Descartes] |
| Full Idea: Descartes rejects logos because it does not achieve the certainty he craves. He replaces it with his own model of rationality, one modelled essentially on mathematics. | |
| From: comment on René Descartes (Meditations [1641], §1) by David Roochnik - The Tragedy of Reason p.76 |
| 2258 | I must even exist if I am being deceived by something [Descartes] |
| Full Idea: Doubtless I exist if I persuade myself of something. But there is some powerful and cunning deceiver who is deliberately deceiving me. Then too there is no doubt that I exist, if he is deceiving me. | |
| From: René Descartes (Meditations [1641], §2.25) |
| 3160 | The Cogito is a transcendental argument, not a piece of a priori knowledge [Rey on Descartes] |
| Full Idea: The Cogito is a transcendental argument; Descartes doesn't claim that it is a priori that he exists, but that any doubt or denial that he exists would presuppose his existence. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Georges Rey - Contemporary Philosophy of Mind 3.2.1 |
| 3849 | "I think therefore I am" is the absolute truth of consciousness [Sartre on Descartes] |
| Full Idea: "I think therefore I am" is the absolute truth of consciousness as it attains to itself. | |
| From: comment on René Descartes (Meditations [1641], §2) by Jean-Paul Sartre - Existentialism and Humanism p.44 |
| 2259 | "I am, I exist" is necessarily true every time I utter it or conceive it in my mind [Descartes] |
| Full Idea: "I am, I exist" is necessarily true every time I utter it or conceive it in my mind. | |
| From: René Descartes (Meditations [1641], §2.25) |
| 6929 | Modern philosophy set the self-conscious ego in place of God [Descartes, by Feuerbach] |
| Full Idea: Modern philosophy set the thinking being, the ego, and the self-conscious mind in the place of the merely ideated being, in place of God. | |
| From: report of René Descartes (Meditations [1641]) by Ludwig Feuerbach - Principles of Philosophy of the Future §37 | |
| A reaction: Descartes would be shocked by this interpretation, but God comes third in his logical priorities, after the existence of his ego, and its reliance on what is clear and distinct. |
| 6914 | Descartes transformed 'God is thinkable, so he exists' into 'I think, so I exist' [Descartes, by Feuerbach] |
| Full Idea: Descartes transformed the proposition 'because God is thinkable, therefore he exists' into the proposition 'I think, therefore I am'. | |
| From: report of René Descartes (Meditations [1641], 2) by Ludwig Feuerbach - Principles of Philosophy of the Future §18 | |
| A reaction: This implies that Descartes' foundation is the Ontological Argument rather than the Cogito. It certainly shows how a priori synthetic thinking is basic in Descartes - that views of existence derive from pure thought. Was Descartes an idealist? |
| 4641 | In the Meditations version of the Cogito he says "I am; I exist", which avoids presenting it as an argument [Descartes, by Baggini /Fosl] |
| Full Idea: Descartes may have been aware of the danger of begging the question (in claiming "I think therefore I am") because in 'Meditations' he says "I am; I exist", which is not presented in the form of an argument. | |
| From: report of René Descartes (Meditations [1641], 2) by J Baggini / PS Fosl - The Philosopher's Toolkit §3.22 | |
| A reaction: Certainly the word 'therefore' cries out for a strict analysis of what is being inferred from what, but presenting the Cogito as a self-evident intuition for the 'natural light' has its own problems. |
| 2260 | If I don't think, there is no reason to think that I exist [Descartes] |
| Full Idea: It could be that if I were to cease all thinking I would then utterly cease to exist. …I am therefore precisely nothing but a thinking thing; that is, a mind, or intellect, or understanding, or reason. | |
| From: René Descartes (Meditations [1641], §2.27) |
| 1117 | The Cogito proves subjective experience is basic, but makes false claims about the Self [Russell on Descartes] |
| Full Idea: The Cogito argument proves that subjective experience is the most reliable, but it makes unjustified claims about the certainty of the Self. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Bertrand Russell - Problems of Philosophy Ch 2 |
| 3120 | Autistic children seem to use the 'I' concept without seeing themselves as thinkers [Segal on Descartes] |
| Full Idea: It really does not seem (as a result of research into autism) that when one thinks of oneself with one's 'I' concept, one must thereby represent oneself as a thinker. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Gabriel M.A. Segal - A Slim Book about Narrow Content 4.2 |
| 5360 | The thing which experiences may be momentary, and change with the next experience [Russell on Descartes] |
| Full Idea: It might be that the something which sees a brown colour is quite momentary, and not the same thing which has some different experience the next moment. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Bertrand Russell - Problems of Philosophy Ch.2 | |
| A reaction: This has become one of the standard objections to the Cogito. Note that Descartes himself was aware of the problem (Idea 1400). Sometimes experiences make no sense if there isn't something connecting them to previous experiences. |
| 2870 | 'I think' assumes I exist, that thinking is known and caused, and that I am doing it [Nietzsche on Descartes] |
| Full Idea: The sentence "I think" contains a series of unprovable assertions; for example, it is I who think, that it must be something at all which thinks, that thinking is by an entity thought of as a cause, that an 'I' exists, and that I know what thinking is. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Friedrich Nietzsche - Beyond Good and Evil §16 |
| 5188 | A thought doesn't imply other thoughts, or enough thoughts to make up a self [Ayer on Descartes] |
| Full Idea: The fact that a thought occurs at a given moment does not entail that any other thought has occurred at any other moment, still less that there has occurred a series of thoughts sufficient to constitute a single self. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by A.J. Ayer - Language,Truth and Logic Ch.2 | |
| A reaction: This seems to be the main objection to the Cogito. It doesn't refute it, but simply recommends cautious restraint in what is being claimed as its conclusion. I can't make much sense of a thought which has no thinker at all. |
| 3624 | That I perform an activity (thinking) doesn't prove what type of thing I am [Hobbes on Descartes] |
| Full Idea: From the fact that I am thinking it follows that I exist, since that which thinks is not nothing. But when he adds 'that is, I am a mind, or intelligence, or intellect', a doubt arises. ..You might as well say 'I am walking, therefore I am a walk'. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Thomas Hobbes - Objections to 'Meditations' (Third) 172 |
| 4526 | The Cogito assumes a priori the existence of substance, when actually it is a grammatical custom [Nietzsche on Descartes] |
| Full Idea: Descartes' Cogito posits as 'true a priori' our belief in the concept of substance, but the idea that when there is a thought there has to be something 'that thinks' is simply a formulation of our grammatical custom that adds a doer to every deed. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Friedrich Nietzsche - The Will to Power (notebooks) §484 | |
| A reaction: This anticipates the sort of thing Ayer and the logical positivists said. It is not clear that Descartes does think the mind is a substance, but this pinpoints a possible presupposition in Descartes. |
| 5579 | How can we infer that all thinking involves self-consciousness, just from my own case? [Kant on Descartes] |
| Full Idea: It seems strange that the condition under which I think is to be valid for everything that thinks, and that on an empirical-seeming proposition we can presume to ground a universal judgement, that everything that thinks has self-consciousness. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Immanuel Kant - Critique of Pure Reason A346 | |
| A reaction: Kant is not bothered by this, and says we know it a priori. If it is indeed an empirical proposition, it becomes an induction with one instance, which is the notorious weakness of the 'argument from analogy' to other minds. The Cogito is not empirical. |
| 5580 | My self is not an inference from 'I think', but a presupposition of it [Kant on Descartes] |
| Full Idea: The simplicity of my self is not inferred from the proposition "I think", but rather the former lies in every thought. 'I am simple' is an immediate apperception, just as the Cogito is tautological, since 'cogito' immediately asserts the reality. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Immanuel Kant - Critique of Pure Reason A355 | |
| A reaction: This is why Kant thinks the self is the result of a transcendental deduction, rather than of a direct observation of the self-evident. Personally I side with Descartes. I do not 'observe' my self, but I am acutely aware of its presence and actions. |
| 5587 | We cannot give any information a priori about the nature of the 'thing that thinks' [Kant on Descartes] |
| Full Idea: If anyone asks me: What is the constitution of a thing that thinks? I do not know how to answer a priori, because the answer ought to be synthetic (for an analytic answer explains thinking, but gives no cognition of that on which thinking rests). | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Immanuel Kant - Critique of Pure Reason A398 | |
| A reaction: This has always seemed a problem with Descartes' very thin account of his 'res cogitans', but then what exactly does Kant want to know? Is it a metaphysical disaster if we think of the self as having no more identity than a geometrical point? |
| 5588 | The fact that I am a subject is not enough evidence to show that I am a substantial object [Kant on Descartes] |
| Full Idea: The fact that I am a subject ..does not signify that as object I am a self-subsisting being or substance; the latter goes too far, and hence demands data that are not encountered at all in thinking. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Immanuel Kant - Critique of Pure Reason B407 | |
| A reaction: This is a key problem with the Cogito - that so little can be said about the 'I' of which the existence has been proved that it is not clear that anything has been proved at all - certainly not that there is a continuous and stable Ego. |
| 13923 | Descartes' claim to know his existence before his essence is misleading or absurd [Descartes, by Lowe] |
| Full Idea: Descartes claimed to know that he existed before he knew what he was - before he grasped his own essence. This is either disingenuous or intended non-literally, if it is not to be dismissed as incomprehensible. | |
| From: report of René Descartes (Meditations [1641], 2) by E.J. Lowe - Two Notions of Being: Entity and Essence 2 n32 | |
| A reaction: If something comes at you from the mist, you can know that it exists before you know what it is. How could you understand the essence of something if you hadn't first encountered its existence? Lowe has it the wrong way round. |
| 6930 | Modern self-consciousness is a doubtful abstraction; only senses and feelings are certain [Feuerbach on Descartes] |
| Full Idea: The self-consciousness of modern philosophy is only a being ideated and mediated through abstraction and thus a doubtful being; certain and immediately assured is only that which is an object of the senses, perception and feeling. | |
| From: comment on René Descartes (Meditations [1641], 2) by Ludwig Feuerbach - Principles of Philosophy of the Future §37 | |
| A reaction: This seems to agree with Hume's empirical doubts about the self (Idea 1316). The comment that 'abstraction' is involved in the Cogito argument is interesting. Descartes said the Cogito was a 'simply intuition of the mind' (Idea 3622). |
| 3623 | The Cogito only works if you already understand what thought and existence are [Mersenne on Descartes] |
| Full Idea: In order to be certain that you are thinking you must know what thought or thinking is, and what your existence is; but since you do not yet know what these things are, how can you know that you are thinking or that you exist? | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Marin Mersenne - Objections to 'Meditations' (Sixth) 413 |
| 1369 | It is a precondition of the use of the word 'I' that I exist [Ayer on Descartes] |
| Full Idea: In the Cogito the work is all done by the demonstrative word 'I', because it is a precondition of the use of such a word that the thing to which it points has to exist. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by A.J. Ayer - The Problem of Knowledge Ch 2 (iii) |
| 2873 | Maybe 'I' am not the thinker, but something produced by thought [Nietzsche on Descartes] |
| Full Idea: In the past one said 'I' is the condition, 'think' is the predicate and conditioned - thinking is an activity which the subject causes; but maybe the reverse is true - and 'I' is only a synthesis produced by thinking. | |
| From: comment on René Descartes (Meditations [1641], §2.26) by Friedrich Nietzsche - Beyond Good and Evil §54 |
| 2261 | My perceiving of things may be false, but my seeming to perceive them cannot be false [Descartes] |
| Full Idea: I now see a light, I hear a noise, I feel heat. Perhaps these things are false, since I am asleep. Yet I certainly do seem to see, hear, and feel warmth. This cannot be false. | |
| From: René Descartes (Meditations [1641], §2.29) |
| 2257 | I myself could be the author of all these self-delusions [Descartes] |
| Full Idea: I myself could be the author of all these self-delusions. | |
| From: René Descartes (Meditations [1641], §2.24) |
| 2279 | A triangle has a separate non-invented nature, shown by my ability to prove facts about it [Descartes] |
| Full Idea: A triangle has a determinate nature, which I did not fabricate, and which does not depend on my mind. This is evident from the fact that various properties can be demonstrated regarding it, such as that its three angles are equal to two right angles. | |
| From: René Descartes (Meditations [1641], §5.64) |
| 6490 | For Descartes, objects have one primary quality, which is geometrical [Descartes, by Robinson,H] |
| Full Idea: Descartes denies any similarity between the physical world and ideas, as matter possesses only geometrical properties; Locke allows more primary qualities, but follows Boyle and the atomists in treating secondary qualities as creations of sense. | |
| From: report of René Descartes (Meditations [1641]) by Howard Robinson - Perception 1.5 | |
| A reaction: The interesting point to note here is that Descartes' geometrical view of objects (they are defined purely by 'extension') is the view that they have one minimal primary quality. I prefer Locke's view, of which the history (given here) is interesting. |
| 2295 | Why does pain make us sad? [Descartes] |
| Full Idea: Why should a certain sadness of spirit arise from a sensation of pain? | |
| From: René Descartes (Meditations [1641], §6.76) |
| 2263 | The wax is not perceived by the senses, but by the mind alone [Descartes] |
| Full Idea: The perception of the wax is neither a seeing, nor a touching, nor an imagining. Rather, it is an inspection on the part of the mind alone. | |
| From: René Descartes (Meditations [1641], §2.31) |
| 3627 | Dogs can make the same judgements as us about variable things [Gassendi on Descartes] |
| Full Idea: A dog certainly makes similar kinds of judgement to your perceiving men by their hats and cloaks when they see their master's hat or clothes, …and they can recognise their master even if he is standing, sitting, lying down, or crouching. | |
| From: comment on René Descartes (Meditations [1641], §2.32) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 272 |
| 2264 | We don't 'see' men in heavy clothes, we judge them to be men [Descartes] |
| Full Idea: Were I to look out of my window and observe men crossing the square, I would ordinarily say that I see the men themselves. But what do I see but hats and clothes, which could conceal automata? Yet I judge them to be men. | |
| From: René Descartes (Meditations [1641], §2.32) |
| 2265 | We perceive objects by intellect, not by senses or imagination [Descartes] |
| Full Idea: Bodies are not, properly speaking, perceived by the senses or by the faculty of imagination, but by the intellect alone. | |
| From: René Descartes (Meditations [1641], §2.34) |
| 2247 | To achieve good science we must rebuild from the foundations [Descartes] |
| Full Idea: Once in my life I had to raze everything to the ground and begin again from the original foundations, if I wanted to establish anything firm and lasting in the sciences. | |
| From: René Descartes (Meditations [1641], §1.17) | |
| A reaction: This sentence is the beginning of the Enlightenment. The project of proving absolutely everything, and in a foundational way, is now met with much scepticism. I will never abandon the project! |
| 2255 | Only one certainty is needed for progress (like a lever's fulcrum) [Descartes] |
| Full Idea: Archimedes sought but one firm and immovable point in order to move the entire earth. Just so, great things are to be hoped for if I succeed in finding just one thing, however slight, that is certain and unshaken. | |
| From: René Descartes (Meditations [1641], §2.24) | |
| A reaction: The classic foundationalist difficulty is that you may find something totally certain, but is it a fulcrum? Or is it just minimal, boring and useless? |
| 2251 | Even if my body and objects are imaginary, there may be simpler things which are true [Descartes] |
| Full Idea: Perhaps even though general things like eyes could be imaginary, still one must admit that certain other things that are even more simple and universal are true. | |
| From: René Descartes (Meditations [1641], §1.20) |
| 6347 | Descartes can't begin again, because sceptics doubt cognitive processes as well as beliefs [Pollock/Cruz on Descartes] |
| Full Idea: Descartes' strategy of starting over will not work, because the skeptic is not just questioning our beliefs, he is also questioning the cognitive processes by which we arrive at our beliefs, and if we start all over again we use the same processes. | |
| From: comment on René Descartes (Meditations [1641], §1) by J Pollock / J Cruz - Contemporary theories of Knowledge (2nd) | |
| A reaction: Scepticism comes in degrees, so there is not one strategy employed by sceptics. It is certainly true, though, that nothing can resist extreme scepticism. The most extreme view is to refuse to accept the meaningfulness of all belief language. |
| 2296 | If pain is felt in a lost limb, I cannot be certain that a felt pain exists in my real limbs [Descartes] |
| Full Idea: I have heard it said by people whose arm or leg has been amputated that they still sensed pain in the lost limb. Thus it does not seem certain that one of my bodily members causes me pain, even though I sense pain in it. | |
| From: René Descartes (Meditations [1641], §6.77) |
| 2249 | It is prudent never to trust your senses if they have deceived you even once [Descartes] |
| Full Idea: The senses are sometimes deceptive, and it is a mark of prudence never to place our complete trust in those who have deceived us even once. | |
| From: René Descartes (Meditations [1641], §1.18) |
| 3620 | We correct sense errors with other senses, not intellect [Mersenne on Descartes] |
| Full Idea: Owing to refraction a stick which is in fact straight appears bent in water. What corrects the error? The intellect? Not at all; it is the sense of touch. | |
| From: comment on René Descartes (Meditations [1641], §1.18) by Marin Mersenne - Objections to 'Meditations' (Sixth) 418 |
| 3619 | The senses can only report, so perception errors are in the judgment [Gassendi on Descartes] |
| Full Idea: Although there is deception or falsity, it is not to be found in the senses; for the sense are quite passive and report only appearances, which must appear the way they do owing to their causes. The error or falsity is in the judgement or the mind. | |
| From: comment on René Descartes (Meditations [1641], §1.18) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 332 |
| 2253 | God may have created nothing, but made his creation appear to me as it does now [Descartes] |
| Full Idea: How do I know that God did not bring it about that there is no earth or heavens, no extension, shape, size or place, and yet that all these things appear to me precisely as they do now? | |
| From: René Descartes (Meditations [1641], §1.21) |
| 2254 | To achieve full scepticism, I imagine a devil who deceives me about the external world and my own body and senses [Descartes] |
| Full Idea: I will suppose an evil genius, supremely powerful and clever, who has directed his entire effort at deceiving me. I will regard all external things as devilish hoaxes, and myself as not possessed of a body or senses, but falsely believing these things. | |
| From: René Descartes (Meditations [1641], §1.22) |
| 2305 | Waking actions are joined by memory to all our other actions, unlike actions of which we dream [Descartes] |
| Full Idea: Dreams are never joined by the memory with all the actions of life, as is the case with those actions that occur when one is awake. | |
| From: René Descartes (Meditations [1641], §6.89) |
| 2294 | I can only sense an object if it is present, and can't fail to sense it when it is [Descartes] |
| Full Idea: Perceptions come upon me without my consent, to the extent that, wish as I may, I could not sense any object unless it was present to a sense organ, nor could I fail to sense it when it was present. | |
| From: René Descartes (Meditations [1641], §6.75) |
| 12271 | Induction is the progress from particulars to universals [Aristotle] |
| Full Idea: Induction is the progress from particulars to universals; if the skilled pilot is the best pilot and the skilled charioteer the best charioteer, then, in general, the skilled man is the best man in any particular sphere. | |
| From: Aristotle (Topics [c.331 BCE], 105a15) | |
| A reaction: It is a bit unclear whether we are deriving universal concepts, or merely general truths. Need general truths be absolute or necessary truths? Presumably occasionally the best person is not the most skilled, as in playing a musical instrument. |
| 12293 | We say 'so in cases of this kind', but how do you decide what is 'of this kind'? [Aristotle] |
| Full Idea: When it is necessary to establish the universal, people use the expression 'So in all cases of this kind'; but it is one of the most difficult tasks to define which of the terms proposed are 'of this kind' and which are not. | |
| From: Aristotle (Topics [c.331 BCE], 157a25) | |
| A reaction: It is particularly hard if induction is expressed as the search for universals, since the kind presumably is the universal, so the universal must be known before the induction can apply, which really is the most frightful nuisance for truth-seekers. |
| 4862 | Can the pineal gland be moved more slowly or quickly by the mind than by animal spirits? [Spinoza on Descartes] |
| Full Idea: I am in ignorance whether the pineal gland can be agitated more slowly or more quickly by the mind than by the animal spirits. | |
| From: comment on René Descartes (Meditations [1641], §6.82) by Baruch de Spinoza - The Ethics V Pref | |
| A reaction: Is this the earliest statement of the problem of double causation? It is a classic difficulty for dualists, highlighted by Ryle, among others. Avoidance of double causation is a classic reason for moving to monism about mind. |
| 3850 | We discovers others as well as ourselves in the Cogito [Sartre on Descartes] |
| Full Idea: It is not only oneself that one discovers in the Cogito, but those of others too. | |
| From: comment on René Descartes (Meditations [1641], §2) by Jean-Paul Sartre - Existentialism and Humanism p.45 | |
| A reaction: The analytical tradition requires a bit more than an instant perception of others in oneself. The problem of 'other minds' must at least be mentioned. However, the way to get to know a universal is to fully study a single instance. |
| 2302 | Faculties of the mind aren't parts, as one mind uses them [Descartes] |
| Full Idea: The faculties of willing, sensing, understanding and so on cannot be called "parts" of the mind, since it is one and the same mind that wills, senses and understands. | |
| From: René Descartes (Meditations [1641], §6.86) | |
| A reaction: It is best here to say that Descartes has confused the 'mind' with the 'person'. These faculties make (I think) no sense without a person to perform them, but the 'mind' surely includes these conscious activities, and many fringe events as well. |
| 3151 | Descartes put thought at the centre of the mind problem, but we put sensation [Rey on Descartes] |
| Full Idea: Descartes confined his dualism to problems of reason and language. Sensation and even imagination seemed to him physically unproblematic. Nowadays it is the reverse: thinking seems easy - but feeling? | |
| From: comment on René Descartes (Meditations [1641], 2) by Georges Rey - Contemporary Philosophy of Mind 2 n16 | |
| A reaction: Thinking only 'seems easy' if it can be done without consciousness, and that is beginning to look like a dubious assumption. The most interesting and promising area is the borderline between a chess-playing machine and a human chess player. |
| 21800 | Descartes mentions many cognitive faculties, but reduces them to will and intellect [Descartes, by Schmid] |
| Full Idea: Although Descartes accepted a variety of cognitive faculties like the intellect, will, power of judgement, imagination, memory, and perception, he took them all to be ultimately reducible to different operations of the will and intellect. | |
| From: report of René Descartes (Meditations [1641], 4) by Stephan Schmid - Faculties in Early Modern Philosophy 2 | |
| A reaction: In Med 4, it is most clear, when he reduces 'judgement' to will and intellect, which enable his to assent to an idea. Nietzsche saw Descartes' view as simplistic. |
| 1399 | Imagination and sensation are non-essential to mind [Descartes] |
| Full Idea: This power of imagination which is in me, in so far as it differs from the power of conceiving, is in no way necessary to my nature or essence. | |
| From: René Descartes (Meditations [1641], §6.73) | |
| A reaction: This is my candidate for the biggest blunder ever made by a great philosopher. But it was thanks to his mistake that I began to realise how totally central imagination is to the very act of thinking. Thank you, René. |
| 1400 | Some cause must unite the separate temporal sections of a person [Descartes] |
| Full Idea: Because the entire span of one's life can be divided into countless parts, each one wholly independent of the rest, it does not follow from the fact that I existed a short time ago that I exist now, unless some cause creates and preserves me each moment. | |
| From: René Descartes (Meditations [1641], §3.49) | |
| A reaction: How could I 'prove' that this computer is the same computer as it was five minutes ago, even after I have accepted the straightforward existence of the computer? This is the Enlightenment Project, the mad desire to prove absolutely everything. |
| 1401 | Since I only observe myself to be thinking, I conclude that that is my essence [Descartes] |
| Full Idea: Since I do not observe that any other thing belongs necessarily to my nature or essence except that I am a thinking thing, I rightly conclude that my essence consists in this alone, that I am a thinking thing, or substance whose essence is thinking. | |
| From: René Descartes (Meditations [1641], §6.78) | |
| A reaction: This actually appears to be my favourite confusion - of episemology with ontology. Compare 'whenever I see him he is smiling, so he must be happy'. Personally I am happy to say that my essence is thinking, as long as it needn't be conscious. |
| 2299 | I can exist without imagination and sensing, but they can't exist without me [Descartes] |
| Full Idea: I can understand myself without the faculties of imagining and sensing, but not vice versa; I cannot understand them without me - a substance endowed with understanding. | |
| From: René Descartes (Meditations [1641], §6.78) | |
| A reaction: I think this is a fundamental and important error on Descartes' part. The idea that understanding is possible without imagination (and even sensation) is wrong, and it leads to the misleading concept of 'pure' reason. |
| 6907 | For Descartes a person's essence is the mind because objects are perceived by mind, not senses [Descartes, by Feuerbach] |
| Full Idea: For Descartes the essence of corporeal things is not an object of the senses, but only of the mind; and hence it is not the senses but the mind that is the essence of the perceiving subject, that is, of man. | |
| From: report of René Descartes (Meditations [1641], 2) by Ludwig Feuerbach - Principles of Philosophy of the Future §17 | |
| A reaction: This, of course, is why Descartes' approach can lead to idealism and solipsism, whereas the other approach leads to empiricism and animalism (Idea 6669). |
| 2283 | Our 'will' just consists of the feeling that when we are motivated to do something, there are no external pressures [Descartes] |
| Full Idea: The will consists solely in the fact that when something is proposed to us by our intellect either to affirm or deny, we are moved in such a way that we sense we are determined to it by no external force. | |
| From: René Descartes (Meditations [1641], §4.57) |
| 2282 | My capacity to make choices with my free will extends as far as any faculty ever could [Descartes] |
| Full Idea: I experience that the will or free choice I have received from God is limited by no boundaries whatever, …indeed it is so great in me that I cannot grasp the idea of any greater faculty. | |
| From: René Descartes (Meditations [1641], §4.56) |
| 2276 | The mind is a non-extended thing which thinks [Descartes] |
| Full Idea: My concept of the human mind is a thinking thing, not extended in length, breadth or depth, and having nothing else from the body. | |
| From: René Descartes (Meditations [1641], §4.53) | |
| A reaction: But he admits (in Med 6) that the mind is so closely integrated with the body that they seem inseparable. Perhaps he shouldn't trust his own concept of the thing, because he is too close to the subject matter. You can't count a crowd if you are in it. |
| 2298 | Mind is not extended, unlike the body [Descartes] |
| Full Idea: Since I am clearly a thinking thing and not an extended thing, and on the other hand I have a distinct idea of a body, as merely an extended thing and not a thinking thing, it is certain that I am really distinct from my body, and can exist without it. | |
| From: René Descartes (Meditations [1641], §6.78) | |
| A reaction: How can he be 'certain' for this reason? This is a classic confusion of ontology and epistemology. Given that the mind is a special case, he should be asking WHY his thinking is clear to him, but his body isn't. Maybe it is because of his viewpoint. |
| 3423 | Descartes is a substance AND property dualist [Descartes, by Kim] |
| Full Idea: Descartes' dualism combines substance dualism and property dualism; two disparate domains of substances, and two mutually exclusive families of properties. | |
| From: report of René Descartes (Meditations [1641], §6.78) by Jaegwon Kim - Philosophy of Mind p.211 | |
| A reaction: I would have thought that substance dualism entailed property dualism. How would you distinguish two substances from one another except by their properties? There seems a merely logical possibility that God gives two substances the same properties. |
| 2303 | The mind is utterly indivisible [Descartes] |
| Full Idea: There is a great difference between a mind and a body, in that a body, by its very nature, is always divisible, but the mind is utterly indivisible. | |
| From: René Descartes (Meditations [1641], §6.85) | |
| A reaction: This strikes me as being simply false. I don't just mean that surgeons can split the mind in half. We should think of the mind as a team of conscious and non-conscious processes, which are held together by a self in normal healthy people. Selves change. |
| 6153 | Interaction between mental and physical seems to violate the principle of conservation of energy [Rowlands on Descartes] |
| Full Idea: It is often argued that any interaction between the physical and the mental - as defined by Descartes - would require a violation of the first law of thermodynamics, the principle of conservation of energy. | |
| From: comment on René Descartes (Meditations [1641]) by Mark Rowlands - Externalism Ch.2 | |
| A reaction: This would be because consciousness is adding energy to the system (in order to generate movement) without it having come from anywhere else in the physical system. A good objection, which only a miracle could overcome. |
| 3625 | The 'thinking thing' may be the physical basis of the mind [Hobbes on Descartes] |
| Full Idea: It may be that the thing that thinks is the subject to which mind, reason or intellect belong; and this subject may thus be something corporeal. | |
| From: comment on René Descartes (Meditations [1641], §2.27) by Thomas Hobbes - Objections to 'Meditations' (Third) 173 | |
| A reaction: Of course, Descartes goes on to reject this view. Presumably he is suggesting that mind etc. might be properties of something corporeal, rather than being identical with it. Descartes was well aware of materialism in Hobbes and Gassendi. |
| 2552 | Knowing different aspects of brain/mind doesn't make them different [Rorty on Descartes] |
| Full Idea: Why should an epistemic distinction reflect an ontological distinction? Why should our epistemic privilege of being incorrigible about how things seem to us reflect a distinction between two realms of being? | |
| From: comment on René Descartes (Meditations [1641], §6.78) by Richard Rorty - Philosophy and the Mirror of Nature 1.2 | |
| A reaction: This strikes me as being one of the most important ideas in philosophy, mainly as a corrective to a lot of bad philosophy, rather than as wisdom offered to non-philosophers (for whom Rorty's thought is probably common sense. How is it? How do we know? |
| 4305 | Descartes gives no clear criterion for individuating mental substances [Cottingham on Descartes] |
| Full Idea: Descartes gives no clear criterion for individuating mental substances. | |
| From: comment on René Descartes (Meditations [1641], §6.78) by John Cottingham - The Rationalists p.86 | |
| A reaction: Presumably I can individuate my own mind by the 'natural light' of reason, and the implications of the Cogito. The minds of others do seem to be a problem. Why should they coincide with bodies, and not overlap or blend or swap? |
| 4861 | Does Descartes have a clear conception of how mind unites with body? [Spinoza on Descartes] |
| Full Idea: What does Descartes understand by the union of the mind and the body? What clear and distinct conception has he got of thought in most intimate union with a certain particle of extended matter? | |
| From: comment on René Descartes (Meditations [1641], §6.82) by Baruch de Spinoza - The Ethics V Pref | |
| A reaction: This is the classic, original and strongest objection to Cartesian dualism - that mind and body are held to be too different to interact. Spinoza may have overreacted a bit when he saw the only solution as the total identity of the two things. |
| 6540 | Even Descartes may concede that mental supervenes on neuroanatomical [Lycan on Descartes] |
| Full Idea: Even Descartes may have conceded that the mental supervenes on the neuroanatomical. | |
| From: comment on René Descartes (Meditations [1641], 6) by William Lycan - Consciousness 5.2 | |
| A reaction: This is true (early in Meditation Six) despite his later suggestion of the pineal gland as the linking point. It proves nothing, but I have heard John Cottingham suggest that Descartes might well be a materialist if he came back today. |
| 7733 | Superman's strength is indubitable, Clark Kent's is doubtful, so they are not the same? [Maslin on Descartes] |
| Full Idea: Descartes's claim that mind and body are separate because the first is necessary when thinking and the second isn't, is like arguing 'Superman's strength is indubitable; Clark Kent's strength is widely doubted; so Clark Kent is not Superman'. | |
| From: comment on René Descartes (Meditations [1641], p.156) by Keith T. Maslin - Introduction to the Philosophy of Mind 2.7.1 | |
| A reaction: I've heard people defend Descartes on this, and Kripke is interesting on the subject, but Descartes had better not be following this pattern of argument, or else a great philosopher would really be presenting an absurdity. |
| 5686 | In some thoughts I grasp a subject, but also I will or fear or affirm or deny it [Descartes] |
| Full Idea: Other thoughts are different from ideas, as when I will, or fear, or affirm, or deny, there is always some thing that I grasp as the subject of my thought, yet I embrace in my thought something more than the likeness of that thing. | |
| From: René Descartes (Meditations [1641], §3.37) | |
| A reaction: Note that the class of mental events we call 'propositional attitudes' had already been identified by Descartes. His categories of thinking in Med. Three might be one of his most important contributions, because that is what matters in the mind. |
| 4017 | Descartes created the modern view of rationality, as an internal feature instead of an external vision [Descartes, by Taylor,C] |
| Full Idea: Rationality is now an internal property of subjective thinking, rather than its consisting in (according to Plato) its vision of reality. This view of Descartes' has become the standard modern view. | |
| From: report of René Descartes (Meditations [1641]) by Charles Taylor - Sources of the Self §8 | |
| A reaction: Greek 'logos' actually seemed to be both internal and external. We have certainly lost the idea that the universe is rational, even though it is ordered. |
| 2284 | I make errors because my will extends beyond my understanding [Descartes] |
| Full Idea: My errors are owing simply to the fact that, since the will extends further than the intellect, I do not contain the will within the same boundaries, but extend it to things I do not understand. | |
| From: René Descartes (Meditations [1641], §4.58) |
| 5685 | True ideas are images, such as of a man, a chimera, or God [Descartes] |
| Full Idea: Some of my thoughts are like images of things; to these alone does the word 'idea' properly apply, as when I think of a man, or a chimera, or the sky, or an angel, or God. | |
| From: René Descartes (Meditations [1641], §3.37) | |
| A reaction: Descartes is obviously aware of a problem with the application of the word 'idea'. This definition seems rather narrow (and visual), but it is certainly confined to concepts, and does not expand to include propositions. |
| 3629 | All ideas are adventitious, and come from the senses [Gassendi on Descartes] |
| Full Idea: I would go further than you and note that all our ideas seem to be adventitious - to proceed from things which exist outside the mind and come under one of our senses. ..The idea of a giant is a man of ordinary size which the mind enlarges at will. | |
| From: comment on René Descartes (Meditations [1641], §3.38) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 280 | |
| A reaction: A classic early statement of modern empiricism. Gassendi needed to think about logic, maths, and necessities to make his case more secure. Where did his idea to 'enlarge' the giant come from? |
| 2273 | The ideas of God and of my self are innate in me [Descartes] |
| Full Idea: The idea of God is innate in me, just as the idea of myself is innate in me. | |
| From: René Descartes (Meditations [1641], §3.51) |
| 2285 | I can think of innumerable shapes I have never experienced [Descartes] |
| Full Idea: I can think of countless geometrical figures, concerning which there can be no suspicion of their ever having entered me through the senses. | |
| From: René Descartes (Meditations [1641], §5.64) |
| 2286 | The idea of a supremely perfect being is within me, like the basic concepts of mathematics [Descartes] |
| Full Idea: The idea of God, that is, the idea of a supremely perfect being, is one discovered to be no less within me than the idea of any figure or number. | |
| From: René Descartes (Meditations [1641], §5.65) |
| 12276 | Justice and self-control are better than courage, because they are always useful [Aristotle] |
| Full Idea: Justice [dikaiosune] and self-control [sophrosune] are preferable to courage, for the first two are always useful, but courage only sometimes. | |
| From: Aristotle (Topics [c.331 BCE], 117a36) | |
| A reaction: One could challenge his criterion. What of something which is absolutely vital on occasions, against something which is very mildly useful all the time? You may survive without justice, but not without courage. Compare Idea 12277. |
| 12277 | Friendship is preferable to money, since its excess is preferable [Aristotle] |
| Full Idea: Friendship is preferable to money; for excess of friendship is preferable to excess of money. | |
| From: Aristotle (Topics [c.331 BCE], 118b07) | |
| A reaction: Compare Idea 12276, which gives a different criterion for choosing between virtues. This idea is an interesting qualification of the doctrine of the mean. |
| 12275 | We value friendship just for its own sake [Aristotle] |
| Full Idea: We value friendship for its own sake, even if we are not likely to get anything else from it. | |
| From: Aristotle (Topics [c.331 BCE], 117a03) | |
| A reaction: In 'Ethics' he distinguishes some friendships which don't meet this requirement. Presumably true friendships survive all vicissitudes (except betrayal), but that makes such things fairly rare. |
| 12281 | Man is intrinsically a civilized animal [Aristotle] |
| Full Idea: It is an essential [kath' auto] property of man to be 'by nature a civilized animal'. | |
| From: Aristotle (Topics [c.331 BCE], 128b17) | |
| A reaction: I take this, along with man being intrinsically rational, to be the foundation of Aristotelian ethics. Given that we are civilized, self-evident criteria emerge for how to be good at it. A good person is, above all, a good citizen. |
| 2280 | Many causes are quite baffling, so it is absurd to deduce causes from final purposes [Descartes] |
| Full Idea: God can make unnumerable things whose cause escapes me, and for this reason alone the entire class of causes which people customarily derive from a thing's "end", I judge to be utterly useless in physics. | |
| From: René Descartes (Meditations [1641], §4.55) | |
| A reaction: anti-Aristotle |
| 12265 | All water is the same, because of a certain similarity [Aristotle] |
| Full Idea: Any water is said to be specifically the same as any other water because it has a certain similarity to it. | |
| From: Aristotle (Topics [c.331 BCE], 103a20) | |
| A reaction: (Cf. Idea 8153) It take this to be the hallmark of a natural kind, and we should not lose sight of it in the midst of discussions about rigid designation and essential identity. Tigers are only a natural kind insofar as they are indistinguishable. |
| 2272 | There must be at least as much in the cause as there is in the effect [Descartes] |
| Full Idea: There must be at least as much in the cause as there is in the effect. | |
| From: René Descartes (Meditations [1641], §3.49) |
| 20645 | Heat is a state of vibration, not a substance [Joule] |
| Full Idea: We consider heat not as a substance but as a state of vibration. | |
| From: James Joule (works [1870]), quoted by Peter Watson - Convergence 01 'Nature's' | |
| A reaction: The puzzle is that giving accurate accounts of vibrations, heat and movement require a quantitative substance, energy. But all we have here is movement, and the denial of a substance. Energy is 'nature's currency system'. |
| 20972 | Joule showed that energy converts to heat, and heat to energy [Joule, by Papineau] |
| Full Idea: James Joule established the equivalence of heat and mechanical energy, in the sense of showing that a specific amount of heat will always be produced by the expenditure of a given amount of energy, and vice versa. | |
| From: report of James Joule (works [1870]) by David Papineau - Thinking about Consciousness App 4.2 | |
| A reaction: This was a major step towards the law of conservation of energy. |
| 2269 | God the creator is an intelligent, infinite, powerful substance [Descartes] |
| Full Idea: I understand by the name "God" a certain substance that is infinite, independent, supremely intelligent and supremely powerful, and created me along with everything that exists. | |
| From: René Descartes (Meditations [1641], §3.45) |
| 2289 | Nothing apart from God could have essential existence, and such a being must be unique and eternal [Descartes] |
| Full Idea: I cannot think of anything aside from God alone to whose essence existence belongs, and I cannot conceive of two or more such Gods. I also perceive that God must be eternal, and have other perfect qualities. | |
| From: René Descartes (Meditations [1641], §5.68) |
| 2275 | It is self-evident that deception is a natural defect, so God could not be a deceiver [Descartes] |
| Full Idea: It is quite obvious that a perfect God cannot be a deceiver, for it is manifest by the light of nature that all fraud and deception depend on some defect. | |
| From: René Descartes (Meditations [1641], §3.52) |
| 2287 | Existence and God's essence are inseparable, like a valley and a mountain, or a triangle and its properties [Descartes] |
| Full Idea: Existence can no more be separated from God's essence than its having three angles equal to two right angles can be separated from the essence of a triangle, or than the idea of a valley can be separated from the idea of a mountain. | |
| From: René Descartes (Meditations [1641], §5.66) |
| 2274 | The idea of God in my mind is like the mark a craftsman puts on his work [Descartes] |
| Full Idea: In creating me, God has endowed me with the idea of God, so that it would be like the mark of the craftsman impressed upon his work, although this mark need not be something distinct from the work itself. | |
| From: René Descartes (Meditations [1641], §3.51) |
| 2288 | I cannot think of a supremely perfect being without the supreme perfection of existence [Descartes] |
| Full Idea: I am not free to think of God without existence, that is, a supremely perfect being without a supreme perfection. | |
| From: René Descartes (Meditations [1641], §5.67) |
| 2268 | One idea leads to another, but there must be an initial idea that contains the reality of all the others [Descartes] |
| Full Idea: Although one idea can perhaps issue from another, nevertheless no infinite regress is permitted here; eventually some first idea must be reached whose cause is a sort of archetype that contains formally all the reality that is in the idea. | |
| From: René Descartes (Meditations [1641], §3.42) |
| 5036 | Descartes cannot assume that a most perfect being exists without contradictions [Leibniz on Descartes] |
| Full Idea: Descartes' error is in assuming without proof that a most perfect being does not involve a contradiction. | |
| From: comment on René Descartes (Meditations [1641], §5.67) by Gottfried Leibniz - A Specimen of Discoveries p.76 | |
| A reaction: Certainly Descartes seems obliged to grasp the concept of God 'clearly and distinctly', so there must be an absence of contradictions. But does Descartes have to prove that there are no contradictions in his concept of a triangle? Is self-evidence enough? |
| 12278 | 'Being' and 'oneness' are predicated of everything which exists [Aristotle] |
| Full Idea: 'Being' and 'oneness' are predicated of everything which exists. | |
| From: Aristotle (Topics [c.331 BCE], 121a18) | |
| A reaction: Is 'oneness' predicated of water? So existence always was a predicate, it seems, until Kant told us it wasn't. That existence is a quantifier, not a predicate, seems to be up for question again these days. |
| 3632 | We mustn't worship God as an image because we have no idea of him [Hobbes on Descartes] |
| Full Idea: We are forbidden to worship God in the form of an image, for otherwise we might think that we were conceiving of him who is incapable of being conceived. It seems, then, that there is no idea of God in us. | |
| From: comment on René Descartes (Meditations [1641], §5.65) by Thomas Hobbes - Objections to 'Meditations' (Third) 180 |
| 3633 | We can never conceive of an infinite being [Gassendi on Descartes] |
| Full Idea: The human intellect is not capable of conceiving of infinity, and hence it neither has nor can contemplate any idea representing an infinite thing. | |
| From: comment on René Descartes (Meditations [1641], §5.65) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 286 |
| 3638 | Existence is not a perfection; it is what makes perfection possible [Gassendi on Descartes] |
| Full Idea: Existence is not a perfection in God or in anything else; it is that without which no perfections can be present. | |
| From: comment on René Descartes (Meditations [1641], §5.67) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 323 |
| 2277 | Since God does not wish to deceive me, my judgement won't make errors if I use it properly [Descartes] |
| Full Idea: Since God does not wish to deceive me, he assuredly has not given me a faculty of judgement with which I could never make a mistake, when I use it properly. | |
| From: René Descartes (Meditations [1641], §4.54) |
| 2278 | Error arises because my faculty for judging truth is not infinite [Descartes] |
| Full Idea: I make mistakes because the faculty of judging the truth, which I got from God, is not, in my case, infinite. | |
| From: René Descartes (Meditations [1641], §4.54) |
| 3636 | God didn't give us good judgement even about our own lives [Gassendi on Descartes] |
| Full Idea: God is not to be blamed for giving puny man a faculty of judging that is too small to cope with everything, but we may still wonder why our judgement is uncertain, confused and inadequate even for the few matters he did want us to decide upon. | |
| From: comment on René Descartes (Meditations [1641], §4.58) by Pierre Gassendi - Objections to 'Meditations' (Fifth) 314 |
| 2281 | If we ask whether God's works are perfect, we must not take a narrow viewpoint, but look at the universe as a whole [Descartes] |
| Full Idea: Whenever we ask whether the works of God are perfect, we should keep in view not simply some one creature in isolation from the rest, but the universe as a whole. | |
| From: René Descartes (Meditations [1641], §4.55) |